This invention relates to imaging apparatus and is particularly applicable to apparatus in which an image, or data representing an image, is formed by a scanning operation. The invention is especially applicable to thermal imaging apparatus.
Thermal imaging apparatus is known in which the thermal image of a scene is scanned optically across a photodetector, the signals from the photodetector are processed and the resulting processed signals applied to a CRT to produce a visible image of the scene. The scanning may be performed by first and second rotating or oscillating reflectors, such as a pair of rotating polygons. Reference may be made to UK Pat. No. 2,110,897 for an example of such a twin polygon scanner. Image distortion may arise in such apparatus.